butterItemFilterField is a jQuery plugin that filters html element with the css class filterable-item.
It is applied to the search field.
If no filter text is entered, then all filterable-items are displayed. Else the search field value is matched against all text contained by a filterable-item.

Example

Filter:

Some filterable item...

Another one.

And yet another one with slightly more text.

This one will not get filtered out because it does not have the class filterable-item.